Table drive for machine tools



March K. F. GALLIMORE 2,343,504

TA BLE DRIVE FOR MACHINE TOOLS Filed Feb. 11, 1942 9 Sheets-Sheet 1fnvenor lie/zh 1". Gallimore 47 fi orvz ya March 7, 1944. GALLIMQRE2,343,504-

TABLE DRIVE FOR MACHINE TOOLS Filed Feb. 11, 1942 9 Sheets-Sheet 2 March7, 1944. GALLIMORE 2,343,504

TABLE DRIVE FOR MACHINE TOOLS Filed Feb. 11, 1942 9 Sheets-Sheet 5frzverzzor Jzezk i'fGaZZi/n ore March 7, 1944. GALLIMQRE 2,343,504

TABLE DRIVE FOR MACHINE TOOLS Filed Feb. 11, 1942 9 Sheets-Sheet4 llw'"jizvenior .Jieiz Flallimor-e March 7, 1944. GALLIMQRE 2,343,504

TABLE DRIVE FOR MACHINE TOOLS Filed Feb. 11. 1942 9 Sheets-Sheet 5 liwezzfor Keih/F Gallimore @W'W f 94 6 I /florne s.

March 7, 1944. FOGALLIMORE 2,343,504

TABLE DRIVE FOR MACHINE TOOLS Filed Feb. 11, 1942 9 Sheets-Sheet 7 F139' -8. I 122 1/8 /2/ 82 o o o o M; w @rmwm jfiorrzgs.

March 7, 1944.

K. F. GALLIMORE 2,343,504

TABLE DRIVE FOR MACHINE TOOLS Filed Feb. 11, 1942 9 Sheets-Shet s March1944- K. F. GALLIMORE TABLE DRIVE FOR MACHINE TOOLS 9 Sheets-Sheet 9Filed Feb. 11, 1942 zmore fig wwwpw Patented Mar. 7, 1944 UNITED STATESPATENT OFFICE TABLE DRIVE FOR MACHINE TOOLS Keith F. Gallimore, Fond duLac, Wis., assignor to Giddings & Lewis Machine Tool (30., Fond du Lac,Wis., a corporation of Wisconsin Application February 11, 1942, SerialNo. 430,377

8 Claims.

horizontal boring, drilling and milling machine of the planer type.

One of the objects of the invention is to provide a novel drivemechanism selectively adjustable to translate the table at a rapidtraverse rate, or at any one of a series of feed rates.

Another object is to provide a new and improved drive mechanism of theforegoing character having shiftable change gears adjustablehydraulically by remote control.

A further object is to provide a drive mechanism of the foregoingcharacter comprising a worm and worm wheel drive unit, and an ad-J'ustable feed unit connected in series to the table and mounted in thebed for the table, and a variable speed electric drive motor connectedto the feed unit and mounted on one side of the bed.

Other objects and advantages will become apparent as the descriptionproceeds.

In the accompanying drawings,

Figure 1 is a fragmentary plan view of the bed of a machine embodyingthe features of my invention, the machine table being removed to showthe table drive mechanism.

Fig. 2 is an enlarged vertical sectional view of a table drive unitforming part of the drive mechanism, taken substantially along line 2-2of Fig. 1.

Fig. 3 is an enlarged transverse vertical sectional view of the tabledrive unit taken along line 33 of Fig. 2.

Fig. 4 is another vertical sectional view taken substantially along line44 of Fig. 2.

Fig. 5 is a fragmentary horizontal sectional view of manual means foractuating the table.

Fig. 6 is a fragmentary detail view of a micrometer for indicating theposition of ad- J'ustment of the table.

Fig. 7 is a longitudinal vertical view of a feed unit in the drivemechanism.

Fig. 8 is a right end elevational view of the feed unit.

Fig. 9 is a left end elevational view of the feed unit.

Fig. 10 is a diagrammatic representation of the feed unit with thegearing shown in plan development.

Fig. 11 is a diagrammatic representation of the hydraulic and electriccontrol system for the feed unit.

While the invention is susceptible of various modifications andalternative constructions, I have shown in the drawings and will hereindescribe in detail the preferred embodiment, but it is to be understoodthat I do not thereby intend to limit the invention to the specific formdisclosed, but intend to cover all modifications and alternativeconstructions falling within the spirit and scope of the invention asexpressed in the appended claims.

Referring more particularly to the drawings, the table drive mechanismconstituting the exemplary embodiment of the invention may be utilizedfor tables or carriages in various types of machine tools, but isespecially suited for and hence shown in connection with the table of ahorizontal boring, milling and drilling machine 01' the planer type. Ingeneral. the machine comprises an elongated horizontal bed I havingspaced parallel guideways 2 formed in the top and extendinglongitudinally thereof. A worktable 8 is supported on the guideways 2for longitudinal reciprocation.

Secured to one side of the bed i substantially midway of its ends is ahorizontal base 4 having guideways 5 for supporting a headstock column(not shown) for translation in a direction perpendicular to the tabletravel. A similar base 6 is secured to" the other side of the bed I, andhas guideways 1 for supporting a tailstock column (not shown) fortranslation in a direction perpendicular to the table travel. It will beunderstood that a spindle head and a tailstock are normally mountedrespectively on the columns for synchronous vertical translation. Theseelements are not shown since per se they form no part of the presentinvention.

The table drive mechanism comprises a novel worm and worm wheel driveunit 8 of heavy duty characteristics which is mounted within the bed Imidway of the ends and on the longitudinal center line, and which isoperatively connected to the table 3 to translate the latter. The driveunit has a power inlet shaft 9 which is connected through a splinecoupling ill to an intermediate shaft H, in turn connected through aspline coupling l2 to the outlet shaft l3 of a table feed unit H.

The table feed unit It is mounted within the rear end of the bed I insubstantial alinement with the drive unit 8, and has a power inlet shaftl5 connected to a reversible variable-speed electric drive motor I6mounted on one side of the bed. The feed unit l4 includes a rapidtraverse clutch l1 for connecting the shaft I5 to the shaft Hi totranslate the table 3 at a high rate of speed, and a feed clutch l8 forconnecting the shafts through a series of selective speed change gearmechanisms to translate the table at different feed plates. Bysuperimposing changes in the speed of the electric motor l6 on the feedunit H, the range and number of available speeds and feeds for the table3 is considerably extended.

The table drive unit The table drive unit 8 comprises a housing 19 whichis suspended within a recess 20 in the bed I. The housing is formed atthe top with a marginal flange 2| resting on and bolted to spacedparallel longitudinal flanges 22 formed in the top of the bed atopposite sides of the recess 20. Removably bolted to one end of thehousing I9 is a gear casing 23 in which the power inlet shaft 9 issuitably journaled. A worm shaft 24 extends longitudinally through thelower portion of the housing I9 and the casing 23, and is suitablyjournaled in spaced antifriction bearings 25, 26 and 21.

Fixed on the power inlet shaft 9 is a gear 29 meshing with a gear 29 ona parallel shaft 30 journaled in the casing 23. A second gear 3| on theshaft 3|! meshes with a gear 32 on the worm shaft 24 to establish areduction gear drive from the power inlet shaft 9 and the worm shaft.

A worm 33 is fixed on the shaft 24 between the bearings 25 and 26, andmeshes with a worm wheel 34 mounted for rotation about a fixed shaft 35extending through the housing l9. In the present instance, the oppositeends of the shaft 35 are reduced in diameter, and are supported inflanged sle wes 36 removably inserted in openings 31 in the oppositeside walls of the housing IS. The sleeves are suitably bolted inposition and project through the openings 38 into the housing I9. Theinner raceways of two axially spaced roller bearings 38 are fittedrespectively on the inner ends of the sleeves 36, and the outer racewaysof the bearings are fitted into opposite ends of a tubular sleeve 39constituting the hub of the worm wheel 34. In the present instance, theworm wheel 34 is annular in form, and has an inner peripheral flange 40interfltting with and bolted to an outer peripheral flange 4| on thesleeve 39 intermediate the ends. A guard housing 42 of arcuate form ismounted in the upper portion of the body housing l9, and substantiallyencloses the upper half of the worm wheel 34, except for a clearanc slot43 in the top through which the upper gear teeth slightly project.

Two large drive gears 44 are rigidly bolted to the ends of the sleeve 39at opposite sides of the worm wheel 34 for rotation therewith, and meshrespectively with two parallel longitudinal gear racks 45 secured to theunderside of the table 3 to complete the table drive connection from thedrive unit 8.

The worm 33 is of the hourglass type, and is formed to havesubstantially full tooth engagement throughout its length with the wormwheel 36 so as to afford a strong and durable drive. The two gears 44meshing with the parallel gear racks 45 also afford a strong, durableand balanced drive connection between the worm wheel 34 and the table 3.Consequently, the table drive unit 8. although compact in size, issturdy and powerful in action, and has load characteristics rendering itespecially advantageous in translating large and heavy tables of thetype commonly employed in horizontal boring, drilling and millingmachines.

Provision is also made for operatingthe table 3 manually through thedrive unit 8, and for indicating the extent of travel of the table. Themanual drive means comprises a worm gear 46 fixed on one end of the wormshaft 24 outside of the bearing 25, and meshing with a worm 41 on atransverse shaft 48 Journaled in the housing I9. The worm 41 has a longlead so that it can be drivenfrom the gear 46. One end of the shaft 48is connected through a spline coupling 49 to an alined shaft 56 which isjournaled in the bed I and extends into a gear casing 5| on one sidethereof. A longitudinal shaft 52, along a side of the bed I, extends atone end into the gear casing 5| wherein it is connected through bevelgears 53 and 54 to the shaft 50. The other end of 'the longitudinalshaft 52 is connected through a spline coupling 55 to a stub shaft 56journaled in and extending through one wall of a gear housing 51 on theside of the bed.

The outer end of the housing 51 is closed by a cover plate 58 having aprojection 59 formed with two parallel bores 60 and 6|. A similarhousing 51 with a cover plate 53 is mounted on the other side of the bedI and the cover plate thereof has an extension 59 with bores 60 and 6|alined crosswise of the machine with the corresponding bores of thehousing supporting the shaft 56. Extending transversely through the bedI is a cross shaft 62 which is rotatably supported adjacent oppositeends by means of bearings 63 mounted in opposite ends of the bores 60.The stub shaft 56 is connected through meshing bevel gears 64 and 85 tothe shaft 62. Each end of the shaft 62 is provided with a micrometerdial 66 which is adapted to be secured in adjusted position by means ofa clamp 61. The dial is formed with suitable graduations 68 which areassociated with a zero point 69 on the beveled end of the projection 59.It will be understood that the dial 66 serves to indicate the extent ofmovement. When desired, the clamp 61 may be released to permitadjustment of the dial 66 in relation to the zero point 69. Thereafter,the dial 66 may again be secured in position so that the continuedmovement of the table 3 may be accurately determined.

Extending through each bore 6| and suitably joumaled therein is a manualactuating shaft 10 by means of which the table 3 may be driven throughthe unit 8 by manual operation upon adjustment of the clutches l1 and I6into neutral position. The shaft 10 is axially slidable and is normallybiased into its outermost position by means of a coiled compressionspring 1| acting against a sleeve 12 pinned to the shaft. A gear 13,fixed on the inner end of the shaft 10, is movable into and out ofmeshing engagement with a gear 14 splined to the cross shaft 62. Theouter end of the sleeve is formed with teeth 15 adapted for engagementby a hand crank (not shown) which may be slipped onto the outer end ofthe shaft 10. By forcing the shaft endwise against the action of thespring 1| to engage the gears 13 and 14, and then rotating the crank,the table will be translated manually. It will be evident that this maybe accomplished from either side of the table.

The table feed unit The table feed unit l4 in its preferred formcomprises two change gear housings and 8| which respectively support thepower inlet shaft I8 and the power outlet shaft I3. In the presentInstance, each housing is formed at the top with side flanges 82 restingon and bolted to spaced parallel longitudinal supporting flanges 83formed inthe top wall of the bed I, and is suspended from the flangeswithin a recess 84 in the bed. The housings respectively enclose twotwo-speed gear mechanisms as hereinafter more fully described which areconnected in series to the power inlet shaft I5 and which areinterconnected by a shaft 85. The rapid traverse and feed clutches I1and I8 are mounted on the power outlet shaft I3 between the housings 80and 8| and are arranged for selective actuation either into neutral, orto connect the shafts I5 and I8 for a rapid traverse drive, orindirectly through the selective speed change gear mechanisms for a slowfeed drive. A sequence of table feeds is obtainable by adjustment of thefeed drive and selective changes in the speed of the driving motor I8.

One end of the power inlet shaft I5 of the feed unit I4 projects fromthe housing 80, and has a sprocket wheel 88 secured thereto. Thesprocket wheel 88 is connected through a silent chain 81 to a sprocketwheel 88 fixed on the shaft of the electric motor I6. The chain 81extends through a suitable opening 89 in one side wall of the bed I. Aguard housing 90 is bolted to the bed I over the opening 89 to enclosethe chain 81 and the sprocket wheel 88.

Fixed on the power inlet shaft I5 within the housing 80 are two gears SIand 92. The gear 9| meshes with a gear 93 on a parallel shaft 94journaled in the housing 80 and located in axial alinement with thepower outlet shaft I3. The rapid traverse clutch II, which is hereinshown as of the disk type, has a driver 95 fixed on the shaft 94 and adriven element 98 connected to the shaft I3. Consequently, when theclutch I1 is engaged, the rapid traverse drive will be established fromthe shaft I5 through the gears 9| and 93, the shaft 94 and the clutch I!to the shaft l3 to translate the table 3 at a high rate of speed, and ina direction determined by the direction of rotation of the motor I8.

The gear 92 is connected to the two-speed change-gear mechanism in thehousing 80, and meshes with a gear 91 fixed on a. stub shaft 98 in axialallnement with the shaft 85. One end of the shaft 98 is formed with apinion 99 and an end clutch element I00. The pinion 99 meshes with agear IOI on a parallel back shaft I02 journaled within the housing 80.Fixed on the shaft I02 is a pinion I03 adapted for meshing engagementwith a gear I04 slidably splined on one end of the shaft 85. The gearI04 is formed with an internal clutch element I05 adapted for engagementwith the element I09 on the shaft 98. Consequently, the gear I04 isshiftable to engage the clutch elements I and I so as to establish adirect drive between the shafts 98 and 85, or into meshing engagementwith the pinion I03 so as to establish an indirect drive between theseshafts through the back shaft I02, thereby providing two differentselective rates of feed.

The two-speed change-gear mechanism within the housing 8I includes theshaft 85 and a parallel shaft I05. Two axially spaced gears I01 and I08are fixed on the shaft I06. Two gears I09 and H0 in a cluster aresplined for axial movement on the shaft 85, and are adapted in oneposition of adjustment to connect the gears I01 and H0, and in anotherposition of adjustment to connect the gears I08 and H0, thereby providing two different feed drives between the shafts 85 and I08. A pinionIII fixed on one end of the shaft I06 meshes with a gear II2 rigid withthe driver 3 of the feed clutch I8. Like the rapid traverse clutchII,the feed clutch I8 is shown as of the disk type, including the driverH3, which in this instance is rotatable about the outlet shaft I3,'and adriven element II4 congreeted to the shaft.

The two clutches I1 and I8 are adapted to be engaged alternately by anactuating collar H8 formed with a peripheral groove I I8 and shiftableaxially through neutral position in opposite directions. A shifter shoeI I1 engages in the groove II 8, and is fixed on a shifter rod I I8extending slidably through the housings and 8| parallel to the clutchaxis. When the shifter rod H8 is in its intermediate position, bothclutches I1 and I8 will be disengaged to interrupt the table drive. Uponmovement of the shifter rod I I8 out of neutral to the right, the feedclutch I8 will be disengaged and the rapid traverse clutch I! will beengaged to establish the rapid traverse drive. Upon movement of theshifter rod I I8 out of neutral to the left, the rapid traverse clutchI1 will be disengaged and the feed clutch I8 will be engaged toestablish feed drive, whereby to translate the table at any one of aplurality of feed rates as determined by the adjustment of thechange-speed gear mechanisms in the feed unit I4 and the speed of theelectric motor I6.

Shifting of the rod H8 is accomplished by a coacting pair of pistons H9,I20, slidable in cylinders I2I and I22, respectively, and to whichpressure fluid is supplied through a pair of twoway valves I23 and I24operated by solenoids I25 and I28. These two-way valves are ofconventional form, being yieldably biased to the positions shown, andactuated to their second or opposite positions by energization of theassociated solenoids. In the present instance, with the solenoids I25and I26 deenergized, pressure fluid is supplied from a tank I21 by apump I28 through a branched pressure line I29 to the valves I23, I24 andthen through lines I38 and I3I to the right and left hand facesrespectively of the pistons H9 and I20, thereby locking the same in theposition shown. Fluid lines I32 and I33, connected with the oppositepiston faces, exhaust fluid from them, through the valves I23, I24 backto the tank I21. The actuator pistons H9, I20 are connected to theclutch actuator rod II8 through a link I34 pivoted intermediate its endsto the rod, and pivotally connected at its outer ends to the pistonrods.

To engage the rapid traverse clutch II, the solenoid I25 is energized,reversing the position of the twoway valve I23. Thereupon, pressurefluid is supplied through the line I32 to the lefthand face of thepiston I I9 to shift it to the right while fluid is exhausted to thetank I21 from the right face of the piston through the line I30. In thisway. the intermediate link I34 is fulcrumed to pull the clutch actuatorrod I I8 to the right to its rapid traverse position. Similarly, toengage the feed clutch I8, and disengage the rapid traverse clutch II,the solenoid I28 is energ zed and the solenoid I25 deenergized.Thereupon, pressure fluid is supplied to the right face of the piston I20 through line I33 and the valve I24, while the piston H9 is returnedto the position illustrated by pressure fiuid supplied through the lineI30 and valve I23. In this way, the link I34 is actuated to shift therod H8 into the extreme left position so as to engage the feed clutchI8. To return the clutch actuator to neutral at any time, the operatorneed only deenergize both the solenoids I25 and I28, whereupon thepistons will be returned to and locked by fluid pressure in the positionshown.

Adjustment of the speed change gear mechanisms is effectedhydraulically, and to this end two hydraulic actuator cylinders I35 andI3 are mounted on the housing 8I.. Two pistons I31 and I38 arereciprocable in the cylinders I35 and I38. The piston I31 is connectedto a shifter rod I39 extending into the housing 80. A shifter shoe I40on the rod I39 engages the gear I04, and serves in opposite positions ofadjustment to move the gear either into mesh with the pinion I03 or intoengagement with the clutch element I00. Similarly, the piston I38 has ashifter rod I4I extending slidably through the housing 8|. A

- shifter shoe I42 fixed on the rod I H engages the gear I09, and servesin opposite positions of adjustment to bring either the gears I08 andH0, or the gears I01 and I09, into mesh.

The supply of pressure fluid to the cylinders I35 and I36 is under thecontrol respectively of two two-position valves I43 and I44 which arenormally biased into one position and which are adapted to be actuatedinto the opposite position by two solenoids I45 and I 48. When bothsolenoids I45 and I48 are deenergized, fluid is supplied from thepressure line I29 through the valve I43 and a line I41 to the right endof the cylinder I35 and through the valve I44 and a line I48 to theright end of the cylinder I35. Upon energization of the solenoids I45and I48, the valves I43 and I44, respectively, will connect the linesI41 and I48 to the tank I21 and will connect the pressure line I29through lines I49 and I50, respectively, to the left ends of thecylinders I35 and I38.

The solenoids I45 and I 48 are controlled by a two-pole four-positionswitch I5I. In the first position of the switch I5I, both solenoids I45and I48 will be deenergized. As a consequence, the

.gears I03 and I04 will be engaged and the gears I08 and H will beengaged to establish the first slow feed drive in the order ofincreasing progression. It will be understood that this rate of feedwill be increased upon increasing the speed of the drive motor I8. Uponmovement of the switch II into the second position, the solenoid I45will remain deenergized, and the solenoid I48 will be connected throughan electric line I52 across supply mains I 53 and I54. As a consequence,the valve I44 will be actuated to connect the line I48 to drain and theline I50 to pressure, thereby shifting the piston I38 to the right so asto disengage the gears I08 and H0 and to engage the gears I01 and I09.This serves to establish the second feed rate in the order of increasingprogression. At the third position of the switch I5I, the solenoid I48will be deenergized and the solenoid I45 will be energized by connectionacross the mains I53 and I54 through a line I55. As a consequence, thepiston I38 will be returned to initial position to reengage the gearsI08 and H0, and the gear I04 will be shifted to the right to engage theclutch elements I 00 and I05. This serves to establish the third feedrate in the order of increasing progression. Upon movement of the switchI5I into the fourth position, the solenoid I45 will remain energized andthe solenoid I48 will be energized to again shift the gear I00 into meshwith the gear I01, thereby establishing the fourth and highest feedrate.

It will be evident that by selective actuation of the switch I5I andadjustment of the speed of the motor I0, any one of a large number 01'feed rates may be obtained. The switch I 5| facilitates control of thefeed rate from a point remote from the table feed unit I4.

I claim as my invention:

1 A drive mechanism for a table reciprocable on a bed comprising, incombination, a worm and worm wheel drive unit mounted in said bed andhaving a drive connection with said table, a feed unit mounted in saidbed and having a drive connection with said drive unit, means fordriving said feed unit, said feed unit including a rapid traverse driveincluding a rapid traverse clutch and a selective feed drive including afeed clutch. said clutches having a common actuator movable throughneutral in opposite directions to alternately engage and disengage saidclutches, a shifter rod connected to said actuator, a lever pivotedintermediate its ends to said shifter rod, two hydraulic piston andcylinder actuators mounted in parallel relation on said unit and havingpiston rods pivotally connected respectively to opposite ends of saidlever, and control means for supplying pressure fluid selectively toopposite ends of said hydraulic actuators whereby to locate the pistonsthereof in phase at the same ends of said actuators to engage one or theother of said clutches, or out of phase in opposed ends of saidactuators to disengage both of said clutches.

2. A drive mechanism for a table reciprocabie on a bed comprising, incombination, a feed unit mounted in said bed and having a driveconnection with said table, means for driving said feed unit, said feedunit including a rapid traverse drive including a rapid traverse clutchand a selective feed drive including a feed clutch and a series ofmultiple speed gear mechanisms with shiftable gear elements, saidclutches having a common actuator movable through neutral in oppositedirections to alternately engage and disengage said clutches, a shifterrod connected to said actuator, a lever pivoted intermediate its ends tosaid shifter rod, two hydraulic piston and cylinder actuators mounted inparallel relation on said unit and having piston rods pivotallyconnected respectively to opposite ends of said lever, control means forsupplying pressure fluid selectively to opposite ends of said hydraulicactuators whereby to locate the pistons thereof in phase at the sameends of said actuators to engage one or the other of said clutches, orout of phase in opposed ends of said actuators to disengage both of saidclutches, a plurality of parallel hydraulic piston and cylinderactuators mounted on said feed unit and connected respectively to saidgear elements, and control means for supplying pressure fluidselectively to opposite ends of said last mentioned actuators whereby toshift said gear elements to obtain different selective feed adjustments.

3. A drive mechanism for a table longitudinally translatable on ahorizontal elongated bed comprising, in combination, a worm and wormwheel drive unit mounted within said bed, a rack and pinion driveconnection between said unit and said table, a feed unit mounted in saidbed and connected to said drive unit and having a terminal inlet shaft,said feed unit being selectively adjustable to provide a rapid traversedrive or a feed drive at any one of a plurality of pre-' set feed rates,and an electric motor mounted in one side of said bed and connected tosaid inlet shaft and selectively operable at difierent preset speeds ofrotation to multiply the speed and feed rates aiiorded by adjustment ofsaid feed unit.

4. A drive mechanism for a table longitudinally translatable on ahorizontal elongated bed comprising, in combination, a first housing anda second housing supported in longitudinally spaced relation in saidbed, a terminal inlet shaft journaled in said first housing, a terminaloutlet shaft journaled in and extending through said second housing andto said first housing, a parallel shaft journaled in said housing inaxial alinement with said outlet shaft and eared to said inlet shaft, 9.rapid traverse clutch including a driver fixed on said parallel shaftand a driven element connected to said outlet shaft, a first changespeed gear mechanism in said first housing geared to said inlet shaftand including a shiftable gear element adjustable selectivelyinto twodifferent positions to provide two selective feed adjustments, a secondchange speed gear mechanism mounted in said second housing and connectedto said first mechanism and including a shiftable gear elementadjustable selectively into two different positions to provide twoselective feed adjustments, afeed clutch having a driver rotatable onsaid outlet shaft and geared to said second mechanism and having adriven element connected to said outlet shaft, means for shifting saidclutch elements simultaneously in opposite directions to alternatelyengage said clutches or to disengage both of said clutches, and meansfor selectively shifting said shiftable gear elements to obtain any oneof a sequence of feed adjustments.

5. A drive mechanism for a table longitudinally translatable on ahorizontal elongated bed comprising, in combination, a feed unit mountedin said bed and operatively connected to said table and including twoadjustable multiple-feed gear mechanisms connected in series, each ofsaid mechanisms having a shittable gear element, two hydraulic actuatorsfor shifting said elements selectively in opposite directions, means forsupplying fluid under pressure, two reversing valves for connecting saidsupply means respectively to said actuators and each valve having asolenoid operator, and electrical control means for said solenoidoperators including a control switch movable successively into differentpositions nally translatable on a horizontal elongated bed comprising,in combination, a feed unit mounted in said bed and operativelyconnected to said table and including two adjustable multiple-feed gearmechanisms connected in series, each of one of a plurality of relativepositions of 'ad- Justment.

7. A drive mechanism for a table longitudinally translatable on ahorizontal elongated bed comprising, in combination, a feed unit mountedin said bed and operatively connected to said table and including twoadjustable multiple-feed gear mechanisms connected in series, each ofsaid mechanisms including a shiftable gear element operable in differentpositions of adjustment to establish different feed rate connections,two hydraulic piston and cylinder actuators having pistons operativelyconnected respectively to said gear elements, two solenoid valves forrespectively controlling the operation of said hydraulic actuators, andelectric circuits including a two-pole four-position switch forcontrolling said solenoid valves whereby to adjust said gear elementsselectively into any one of their relative positions oi! adjustment.

8. A drive mechanism for a table longitudinally translatable on ahorizontal elongated bed comprising, in combination, a feed unit mountedin said bed and operatively connected to said table and including twoadjustable multiple-feed gear mechanisms connected in series, each ofsaid mechanisms including a shiftable gear element operable in differentpositions of adjustment to establish different feed rate connections,two hydraulic piston and cylinder actuators having pistons operativelyconnected respectively to said gear elements and extending parallel tothe direction of movement thereof, solenoid valve means for controllingsaid actuators, and electric circuits including switch means adjustablesuccessively into difierent positions to efiect operation of saidactuators in a predetermined sequence, whereby to adjust said gearelements successively into different relative positions to whereby toobtain a progression of predetermined effect a progression of feedchanges.

feed changes.

6. A drive mechanism for a table longitudi- KEITH F. GALLIMORE.

